Q: I am a 25 years old female. Some months back I went to the doctor with a complaint of fatigue thinking my iron was low. When the blood work was done, my platelet count was low (77 or something). He sent me to a haematologist and said that I had monocelios. So they made me an appointment for a follow-up in 3 months but even then they were low. Today I had a cat scan done and need to go for a bone marrow test. I don't truly understand what they are looking for. What is your opinion. Do you think that the bone marrow test is really needed? Could you please give me some advice and tell me what you think?

A:Platelets (thrombocytes) are a type of blood cells, which are derived in the bone marrow from large cells called megakaryocytes. They are critical for the clotting of blood and have life-span of about 10 days. The normal platelet count ranges from 150,000 - 400,000/ml and a reduction in platelets is referred to as thrombocytopenia. This may be mild (100,000 - 150,000/ml), moderate (50,000 - 100,000/mlƒw) or severe (less than 50,000/ml). Platelets may be low due to: a) increased destruction (immunologic ¡V infections, drugs; gestational thrombocytopenia) or utilization (disseminated intra-vascular coagulation; abnormal vasculature as seen in haemolytic uremic syndrome & thrombotic thrombocytopenic purpura), b) decreased production (leukaemia, aplastic anaemia, megaloblastic anaemia, drugs, infections or c) sequestration in the spleen (cirrhosis of liver). Idiopathic thrombocytopenic purpura (ITP) is the presence of isolated thrombocytopenia with a normal bone marrow and the absence of other causes to account for it. There are two distinct types -acute ITP in children and chronic ITP in adults. No treatment is required when the platelet counts are more than 50,000/ml. Treatment is indicated a) when platelets are less than this and there is significant mucous membrane bleeding; b) in patients with hypertension, peptic ulcer disease or vigorous lifestyle who have a risk factor for bleeding and c) when platelet count <20,000-30,000/ml. Glucocorticoids and intra-venous gammaglobulins (I.V. Ig) are the mainstays of medical therapy. Their use and dose is dictated by the symptoms, patients clinical condition and the platelet count. Platelet transfusion is indicated for controlling severe haemorrhage. Platelet survival is increased if the platelets are transfused immediately after I.V. Ig infusion. A bone marrow examination may be done to exclude the possibility of other underlying conditions which may be associated with thrombocytopenia. The decision will be based on your clinical condition and other lab reports.